Add modal graph node inspection

SLICE_HISTORY.md

@@ -1,5 +1,34 @@
 # Completed slices
 
+## DFG-12 modal node inspection
+
+### Changed
+
+- Released the fixed `graph-browser@3` template with a native modal node inspector.
+- Made graph-node activation inspect full validated node metadata and content without replacing the
+  current neighborhood or viewport.
+- Added mouse and keyboard activation plus Escape, explicit close controls, and backdrop dismissal.
+- Added a separate Explore neighborhood action for intentional graph recentering.
+- Kept the existing token-bound, read-only HTTP surface and exact-node endpoint unchanged.
+- Released the compatible change as DocForge 0.7.2.
+
+### Verification
+
+- Focused HTTP interaction-contract checks cover the dialog, inspection handler, and explicit
+  neighborhood action.
+- Embedded JavaScript syntax validation and the complete warning-strict DocForge suite pass.
+
+### Limits
+
+- Dialog state is session-local and is not persisted in the URL.
+- Node content remains plain text and is not rendered as trusted HTML.
+- The right sidebar continues to describe the current root neighborhood.
+
+### Next gate
+
+No further gate is planned. Measure graph-browser use before adding history, comparison, or editing
+surfaces.
+
 ## DFG-11 graph viewport navigation
 
 ### Changed